A standard motor-vehicle door has an outer door panel, an annular inner door panel including a front, rear, upper, and lower frame members fixed to the outer door panel and defining an opening. An insert fits in the opening and carries mechanical, electromechanical, and electronic subassemblies. Fasteners retain the insert on the inner door panel. The subassemblies can include the door latch, an air bag, a controller, the inside door handle, the window and its operating mechanism, and one or more loudspeakers.
It is standard to use a so called window cassette as the insert. This is therefore a fairly complex assembly that must be meticulously fitted and secured to the inner door panel. This job is particularly complex because the window part must be fitted up through the slot formed between the upper frame member of the inner panel and the outer panel.
German patent 4,426,426 of Morando described a system where the window and its mounting hardware are pivotally mounted on the insert. Such an arrangement facilitates assembly, but substantially increases the cost of the window cassette.
In another system described in German patent document 195 24 232 of Rodermund the insert is fitted in the annular inner door panel, normally slipped up from below. The door latch is subsequently passed through a hole in the insert and special seals and the like are provided to subdivide the interior of the door into an outer so-called wet compartment into which water may gain entry along the lower edge of the window and an inner dry compartment holding the fragile and moisture-sensitive electrical and mechanical components. Assembling such a door is a multistep operation involving fitting in the insert, securing it in place, then mounting the latch and seals and securing them in place.